Ovarian cancer remains difficult to detect in its early stages. That’s unfortunate because survival rates for women increase dramatically when the disease is caught and treated early. Researchers are working hard to improve detection and treatment, but much remains to be done.
|Robert Morgan Jr. (Photo by Kaminsky Productions)|
Robert J. Morgan Jr., M.D., professor in the Department of Medical Oncology and Therapeutics Research and co-director of City of Hope’s Gynecological Oncology/Peritoneal Malignancy Program, has studied ovarian cancer and treated women battling the disease for more than two decades. In the first of a two-part series, he explained some of the challenges physicians face in detecting the disease and touched on some possible ways they might overcome those barriers.
eHope: Why is ovarian cancer so difficult to find in its early stages?
Robert J. Morgan Jr., M.D.: The major problem is that the ovaries are located deep in the pelvis. Until recently it was thought that patients with early-stage ovarian cancer did not have any symptoms or that symptoms were non-specific and related to other issues. More recently, published research suggests that many women with ovarian cancer may indeed have early symptoms. We now include these symptoms in the National Comprehensive Cancer Network guidelines for detecting ovarian cancer.
EH: What are these early signs?
RM: Pelvic or abdominal pain, feeling full quickly when eating, high urinary urgency or frequency and increased abdominal size or bloating. These symptoms have to occur at least 12 days per month and be present for less than one year before we would consider more invasive testing to confirm ovarian cancer. National clinical research groups are designing a clinical trial to confirm that using these symptoms will improve screening.
EH: Are there any clinical screening methods doctors use?
RM: Unfortunately, there presently are no standard recommendations for routine screening in the general population, mostly because there haven’t been any trials that have documented a greater benefit than the annual gynecologic exams and care we currently give.
EH: Some have talked about testing for CA-125. Should that play a part in screening?
RM: The CA-125 blood test looks for a substance (a glycoprotein) in the bloodstream. About 70 to 80 percent of advanced ovarian cancers make the body produce this substance, but the amounts of that protein don’t always relate to the amount of cancer. Some patients with a lot of cancer will have low CA-125 levels, and some patients with less cancer will have high CA-125 levels.
Unfortunately, it isn’t a good indicator of early ovarian cancer, either, because only about half of patients have elevated levels of it in their blood. There also are many other conditions, both cancer and non-cancer, that can cause an elevated CA-125 level. Some large ovarian cancer screening studies are using this in addition to endovaginal ultrasound to see if early detection is possible. It isn’t, however, recommended for routine use at present.
The primary use of CA-125 has been to follow advanced ovarian cancer patients during their treatment, and until now it has been recommended for follow-up of patients who have been treated but are in remission. The usefulness of this approach, however, has been called into question. A large clinical trial in Europe tracked CA-125 levels in women in remission from the disease. Women whose CA-125 levels grew to twice normal either were treated right away or were followed until clinical symptoms confirmed ovarian cancer and then were treated. The study showed no difference in survival either way. However, the women who were treated earlier had a worsened quality of life. So although we need to take a closer look, it seems that CA-125 levels may not work for routine follow-up, either.
EH: Are researchers evaluating any new screening methods, and do they seem promising?
RM: At present there are several methods under study, primarily involving screening of protein patterns or DNA in the bloodstream to see if these substances can be detected in very early stages of ovarian cancer. All of these approaches are experimental, but patients and doctors are all hoping that a breakthrough will be possible.
Read part two in next month's eHope when, Mihaela Cristea, M.D., assistant professor of medical oncology, will conclude this article with insights into what women can do to protect themselves from ovarian cancer.